Fix cli bug, cleanup and enhancement

[naik-aakash]

Closes #254

Todo

• [×] Add test with poscar.lobster
• [×] Add option for spin-polarized plots in cli for automatic analysis

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 96.22642% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 97.41%. Comparing base (320fec0) to head (275168d). Report is 1 commits behind head on main.

Files	Patch %	Lines
lobsterpy/cli.py	95.91%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #256 +/- ## ========================================== - Coverage 97.51% 97.41% -0.11% ========================================== Files 12 12 Lines 2700 2669 -31 ========================================== - Hits 2633 2600 -33 - Misses 67 69 +2 ```

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[JaGeo]

I will test it tonight when you say it is okay ;). Then, I will release a new version.